It has long been a feature of many types of compositions, including cosmetic compositions, that they comprise a fragrance oil for the purpose of delivering a pleasant smell. This can improve the overall consumer acceptance of the composition or mask unpleasant odours. In fact, it can be the sole purpose of some compositions to impart a pleasant odour to the skin, hair or other suitable surface.
Fragrance compositions, broadly speaking, comprise a fragrance oil, or a mixture thereof; and a carrier, or a mixture thereof. Each fragrance oil itself usually comprises many different perfume raw materials with each perfume raw material differing from another by several important properties including character, volatility, olfactory detection (known as the odour detection threshold) and the like. By bearing in mind these different properties, and others, it is possible for highly skilled perfumers to blend different perfume raw materials to develop a fragrance oil with a specific overall character profile. It is usual that the character is designed to develop, alter and mature over time as the different perfume raw materials evaporate from the surface and are detected by the user. For example, perfume raw materials which have a high volatility are commonly used within a fragrance oil to give light, fresh, fruity, citrus, green or delicate floral characters to the fragrance oil, which fragrance characters are detected soon after application. Such materials are usually referred to in the field of fragrances as “top notes”. By way of a contrast, the less volatile perfume raw materials are typically used to give characters such as musk, sweet, balsamic, spicy, woody or heavy floral to the fragrance oil which, although they may be detected soon after application, also last for longer. These materials are usually referred to as “middle notes” and/or “base notes”.
To date, one of the limiting factors for perfumers when designing specific fragrance characters has been the physical characteristics of the perfume raw materials. As such, it has only been possible to develop fragrance oils which impart a “top note” character for a short period of time. This is because the top note perfume raw materials are highly volatile and therefore rapidly evaporate from the surface. Therefore, any lasting element of a fragrance has been achieved by using middle and base notes, which in turn restricts the achievable character. Blending of higher levels of top note perfume raw materials into a fragrance oil does not improve the long lasting nature of the “top note” fragrance character, but instead may result in a stronger initial burst of “top note” fragrance character which still quickly evaporates.
It is known that consumer preference for fragrance compositions is mostly driven by the initial “top note” fragrance character impression, so that it is desired to prolong the “top note” character impression over time. It is therefore desirable to have a method of fragrancing a surface, in particular, skin and/or hair, wherein the user perceives a long lasting overall fragrance character combination arising from the respective fragrance characters of the first and second compositions, which is not achievable by conventional perfumery means. This allows the formulator to select, for example, specific desired fragrance characters for complexing in the first composition, so as to provide those desired, preferably “top note”, fragrance characters over time from the first composition, and to select balancing fragrance characters for release from the second composition. Furthermore, it would be advantageous to create a method of fragrancing a surface, in particular skin and/or hair, wherein one or several well recognised fragrance characters, and particularly “top note” fragrance characters, are combined from the respective fragrance characters of the first and second compositions and are maintained over a substantial period of time, such that unique overall long lasting, “top, middle and base note” character combinations are created. Finally, it would be advantageous to develop a kit or package for use with such a method wherein the consumer is able to use different compositions within the kit or package to create fragrances with different fragrance character combinations.
In the past, many attempts have been made to alter and prolong the volatility profiles of fragrance oils to extend the overall fragrance effect within many types of compositions. For instance, the fragrance oil may be formulated to include a higher proportion of perfume raw materials with a low volatility, i.e. of “middle and base note” character. However, as discussed above, this restricts the fragrance character that can be achieved over time. Another approach has been to chemically, and reversibly, modify the perfume raw materials to form a pro-perfume compound as disclosed in patent applications WO 98/47477; WO 99/43667; WO 98/07405; WO 98/47478; all of which are incorporated herein by reference. The resultant pro-perfumes are not themselves volatile but, after the chemical modification is reversed, usually by hydrolysis upon application to the surface, the perfume raw material is released and can then evaporate in the usual way. In these applications, the release rate of the perfume raw materials is controlled by the reaction rate for transforming the pro-perfume to perfume raw material. Whilst pro-perfumes enable the release of a specific perfume raw material to be delayed, it is impractical to use them to stagger the release of materials such that unique fragrance character combinations are achieved over time.
Further disclosures have discussed improving the overall longevity of a fragrance by delaying the evaporation of the fragrance oil(s), for example, by encapsulating the perfume raw materials (disclosed in JP-A-58/052211, EP-A-303,461); absorbing the materials onto a surface, for example, by using carbon or zeolites (disclosed in U.S. Pat. No. 6,033,679); occluding the release of the perfume raw materials, for example, by the formation of a film (disclosed in U.S. Pat. No. 3,939,099); and complexing the perfume raw materials, for example, by using cyclic oligosaccharides. The prior art on this latter method includes JP-A-6/287127 and JP-A-8/176587 which disclose use of hydroxyalkylated cyclodextrins within cosmetic, single phase, alcoholic based solutions or dispersions to sustain the effect of the fragrance; and JP-A-8/183719 and JP-A-10/120541 which disclose a combination of cyclodextrin encapsulated fragrance and non encapsulated fragrance within a solid, liquid or aerosol deodorant composition for prolonging the fragrance duration to at least 2 hours, all of which are incorporated herein by reference. Cyclodextrins have also been used with fragrances within cosmetic compositions to improve the solubility of the fragrance oils within the base matrix. The prior art in this area includes JP-A-62/161720 and JP-A-63/192706 which disclose the use of cyclodextrins in fragranced water based compositions. It is expected that these compositions will also have some degree of sustained fragrance release although this is not commented upon in either of these applications.
Whilst the compositions and disclosures of the prior art provide useful teachings for prolonging the fragrance character of a cosmetic composition as a whole, these approaches still have limitations. The cyclic oligosaccharide(s), when used in the traditional way in a single phase solution, interact with a broad range of perfume raw materials present, including “top, middle and base notes”, thereby prolonging the overall character of the whole fragrance and not that of any one character specifically. Furthermore, the prior art does not teach how to develop a method for fragrancing a surface, in particular skin and/or hair, which can achieve prolonged enhancement of, for example, specific fragrance characters delivered from the first composition, for example, specific “top note” fragrance characters, in combination with the same or another fragrance character delivered from the second composition, to achieve a unique combined fragrance character profile over time.
Surprisingly, it has now been found that a method for fragrancing a surface, preferably skin and/or hair, which method comprises applying to one area of the surface, preferably skin and/or hair, a first composition comprising a solution or dispersion of a complex, the complex comprising at least one first cyclic oligosaccharide and at least one first fragrance oil, the complex being dissolved or dispersed in a first solvent, or mixture thereof, in which the first solvent or mixture thereof has a dielectric constant at 25° C. of greater than or equal to 43, preferably greater than or equal to 45, followed by simultaneously or sequentially, in either order, applying to the one area or an area adjacent thereto, a second composition comprising a solution or dispersion of at least one second fragrance oil which may be the same or different from the at least one first fragrance oil, optionally, but not necessarily, at least one second cyclic oligosaccharide which may be the same or different from the at least one first cyclic oligosaccharide, in a second solvent, or a mixture thereof, long lasting fragrance and/or unique character combinations can be created by the appropriate selection of first and second fragrances, which combinations would not have been possible to develop using traditional perfumery. In addition, it has also been found that, once the surface has been fragranced according to the method above, fragrance release from the first composition (and the second composition, if the second composition additionally comprises at least one second cyclic oligosaccharide) can be enhanced over time, either naturally (as fragrance blooms) or deliberately (as fragrance refreshings), to release periodic and unexpected blooms or refreshings, as appropriate, of the specific one or several fragrance characters from the first composition and from the second composition, if the second composition additionally comprises at least one second cyclic oligosaccharide.
This invention can be further enhanced by selecting different fragrance oils for each of the first and second compositions such that they impart different, preferably balancing, desired characters to the overall impression perceived by the consumer. In addition, by using high odour impact “top note” perfume raw materials in the first composition, the user experiences both long lasting and periodic enhancements of “top note” fragrance character throughout usage.
The invention can be enhanced still further by optionally incorporating at least one second cyclic oligosaccharide into the second composition, which, whilst not wishing to be bound by theory, is believed to form a complex association with the at least one second fragrance oil upon the surface. Addition of at least one second cyclic oligosaccharide to the second composition further acts to delay the release, and enables periodic enhancement, of the second fragrance character as a whole. Again, by careful selection of the perfume raw materials of the second composition, and in conjunction with the fragrance character combination from the first composition, the desired overall fragrance character can be achieved.
Finally, this invention can be enhanced even further by the development of kits and delivery packages wherein the user is able to use a variety of different first and/or second compositions to create his/her own fragrance character combination.
It is an object of the present invention to provide a method of fragrancing a surface, preferably skin and/or hair, which imparts to the user a fragrance character combination, of a long lasting fragrance character, particularly, a “top note” fragrance character, from the first composition, combined with a balancing fragrance character from the second composition, throughout usage. It is a further object of this invention to provide a method of fragrancing a surface, preferably skin and/or hair, which produces noticeable enhancements of fragrance character throughout usage. These, and other objects of this invention, will become apparent in the light of the following disclosure.